Rocket fuze



United States Patent ROCKET FUZE Casper .l. Keeper and Francis P. Gilhooly, Huntsville,

Ala., and Samuel Wassermau, Washington, D. C., assignors to the United States of America as represented by the Secretary of the Army Application October 9, 1951, Serial No. 250,557

6 Claims. (Cl. 102-49) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described in the specification and claims may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to a useful improvement in fuses and more particularly to a novel fuse arming organization for use in a rocket projectile whereby the projectile cannot be accidentally or prematurely exploded.

Accordingly it is a general object of our invention to provide a rocket fuse that is positive in action and is sturdy in construction.

Another object of our invention is to provide a safety device that is compact and reliable.

it is a further, and more specific object of our invention to utilize the gas pressure arising within the combustion chamber of a rocket projectile during motion thereof to initiate the arming cycle of a fuse.

The embodiment of my invention is illustrated in the drawings in which:

Figure l is a longitudinal section view of a rocket showing the manner of construction of the fuse arming structure.

Figure 2 is a cross section view of the assembly of Figure 1 taken on lines 22.

Figure 3 is an enlarged perspective view of the bore riding pin of Figures 1 and 2.

Referring now more particularly to the drawings in which corresponding reference characters refer to like parts throughout 1 represents a rocket launcher tube holding therewithin a rocket shown generally as 2. In the forward part of the rocket is the usual explosive charge 3 with a booster charge 4 immediately to the rear thereof. The booster is confined within a cylindrical disk 6 threaded into annulus 8 which in turn threaded into the rocket casing 5. Annulus 8 embracesprimer "19 disposed rearwardly of booster 4 and retains the same in aligned position with the firing pin. Port 12 of smaller diameter than the primer recess lies rearwardly of primer and opens into firing pin cavity 14 to permit entry of the firing pin during the firing cycle as will later appear. Between firing pin cavity 14 and port 12 extends the flat 15 of bore riding pin 18 which acts as a positive bar to the entry of the firing pin into port 12 when the fuse is disarmed. Bore riding pin 18 is a straight cylindrical rod having a cap 22 secured to one end thereof and a helical spring 24 coaxial therewith and bearing against the cap to urge the same outward. Disposed substantially one fourth the length of the rod from the cap end is a radial bore 19 for a purpose to be later explained. For a distance of approximately one half the length of the rod one side thereof is removed to form a flat; a recess is cut into the flat for guiding the firing pin; and the shoulders bounding the recess are cut away as at to form a narrow tip for a purpose that will later appear.

Cylindrical interlocking member 26 is longitudinally slidable in a bore 32 and terminates at its rear end in the frustum of a cone 28 carrying an ear 30 thereon. The cylindrical member has a portion thereof cut away to form a reduced diameter suflicient to form a seat for spring 34 and slidably fit at its front end and pierce bore 19 of member 13. Spring 34 yieldably bearing on seat 36 urges ear 30 to interfere with rod 38 laterally slidable in a cylindrical passage. Rod 38 has substantially round extremities, the lower of which engages 2,704,033 Patented Mar. 15, 1955 2 the upper edge of mushroom piston 40 which is in turn secured by piston rod 42 to fuse diaphragm 44.

Fuse diaphragm 44 acts chiefly as a gas seal as will presently be explained and the edges thereof are tightly clamped into abutting relationship with body member 46 by gland 48 threaded thereon. The diaphragm in practice consists of a formed steel disc approximately 0.02 inch in thickness having a central pad 54 and a concentric arcuate ring 50 pressed therein. The ring is to permit axial motion of the center of the disc without undue stress or rupture of the metal. Vents 52 lead from the diaphragm chamber radially outward to prevent a pressure build up on the rearward side of the diaphragm. Pad 54 abuts cylindrical connecting rod 56 which is longitudinally slidable in a bore in gland 48 and is threadedly engaged with boss 58 of 'inotor diaphragm 6G. Machining tolerances between connecting rod 56 and its bore are kept to the minimum commensurate with free relative motion to prevent the passage therebetween of rocket motor gases. A ridge 62 of soft solder or other suitable bonding metal is applied around the exit of the connecting rod bore to act as a further sealing means. Motor diaphragm is a soft steel disc and in practice is approximately 0.04 inch thick. Combustion chamber housing 63 is secured onto the rearward end of gland 48 and clamps disc 60 therebetween. Propellant powder grains 64 are carried within the combustion chamber housing and supply the en ergy for rocket travel in the well known manner.

Referring now to the firing pin and its associated appurtenances it will be understood that in practice an all ways type of pin is used to insure explosion of the charge whenever and however a target is hit, but since the specific pin forms no part of this invention a simple pointed pin is disclosed in the interests of simplicity. The firing pin cavity 14 is cylindrical and has therein liner 68 substantially shorter in longitudinal dimension than the cavity and forming a seat for a biasing spring 70. Sleeve 72 lies within and concentric with liner 68 and has a turned out flange 73 on the rearward end to engage the rearward end of spring 70. The pointed firing pin 74 is secured to or made integral with plun er 75 which includes an integral flange 76 to bear against flange 73. It should be here noted that liner 68 and sleeve 72 are cut away at the upper part whereby they straddle bore riding pin 18, and sleeve 72 engages at its lower part and bears against the flat 20 of the bore riding pin.

Operation When the burning of the powder grains 64 is initiated the products of combustion are discharged at high velocity and pressure from an outwardly flared nozzle at the rear of the rocket (not shown) and a high level of pressure is rapidly built up in the combustion chamber. This pressure is applied to motor diaphragm 60 which will bend in a forward direction thereby movably sliding connecting rod 56 which forces against pad 54 and flexes the midpoint of fuse diaphragm forward. Piston rod 42 and mushroom piston 40 are urged forward thereby uncovering the lower end of rod 38 which will be cammed down into the mushroom piston cavity by frusturn 28 as spring 34 forces interlocking member 26 in a rearward direction. It will be noted that the motion of rod 38 into the cavity effectively prevents piston 46 from returning to its original position even after the combustion chamber pressure falls. Urging of member 26 rearward removes it from the bore 19 of bore riding pin 18. During this time the reaction forces created by the combustion of the propellant have moved the rocket clear of the launcher and spring 24 will cause bore riding pin to fly out of its chamber and fall to the ground. Removal of the bore riding pin clears the path of travel of sleeve 72 and upon impact of the rocket with a target, plunger 75 will move violently forward against the urging of spring and enter port 12 to detonate primer 10 and fire the charge.

It can be seen that we have invented a positive acting rocket fuse that is reliable in action yet is simple and inexpensive to manufacture. It is however to be understood that our device may, if desired be used in conenemas junction with any projectile. While we. have here shown -a preferred embodiment of, our invention it will be unof travel thereof, locking means for said member, a

bowed disk operatively connectedto said locking means and a pressure sensitive. diaphragm connected to said 2. The invention as set. forth in claim I wherein said piercing said bore riding pin at one end thereof, a rod engaged by the said slidable member at the other end thereof, a piston arranged in normally edgewise interfering relationship with said rod, a bowed disc connected to said piston, a pressure responsive diaphragm arranged to be influenced by combustion chamber pressure and operatively connected to said bowed disc whereby to flex the same and move the said piston out of interfermgrelationship with said rod to allow said spring urged slidable member to remove from piercing relationship with said bore riding pin to deliver the same to the influence of said spring to eject such bore riding pinfrom the rocket.

5. The invention according to claim 4 wherein the said slidable member is shaped to form a truncated cone 7 at the said other end thereof toimpart a camrning action locking means comprises a spring biased cylindrical bar 2 piercing said member..

3. In a percussion fuse adapted to be carried by a rocket having a combustion chamber, in, combination, a primena firing pinnormally held in spaced relation with said primer, a pin, in part at least between said primer and said firing pin, a spring urging said pin outwardly of. said rocket, a slidable member piercing said pin at one end thereof, a, rod engaged by the said slidable member at the other end thereof, a piston associated in normally edgewise interfering relationship with said rod, 9. bowed disc connected to said piston, a pressurev sensitive diaphragm arranged to be influenced by combustion chamber pressure and operatively connected to said bowed disc whereby to flex the same and move the said piston out of interfering relationship with said rod to allow said spring urged slidable member to remove from piercing relationship. with said pin.

4. In a percussion fuse adapted to be carried by a rocket havinga combustion chamber and adapted to be held in the bore: of a launching tube comprising a primer, :1 firing pin normally held. in spaced relation with said primer, a bore; riding, pin in part at least between said primer and said firing pin, a spring urging said bore riding pin outwardly of said rocket, a slidable member between said firing pin and said primer, a connection,

between said disc and said bore riding pin locking the said pin in said safety position, and resilient means urging said bore riding pin outwardly of said rocket whereby distortion of said diaphragm operates to flex said bowed disc to remove the connection between the said disc and the said bore riding pin and deliver the same to the influence of said resilient means to eject said bore riding pin from the rocket.

References Cited. in the file of this patent UNITED .STATES PATENTS 1,375,466 Ragsdale Apr. 19, 1921 1,806,877 Hale May 26, 1931 2,145,507 Denoix Jan. 31, 1939 2,479,582. McCaslin Aug. 23, 1949 

